QFD - Quality Function Deployment

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• See also SixSigmaDmadvMeasure

(Bij07,p6): Problem solving methods focus on reducing defects, is like "Scraping burnt toast" -- Dr. Deming.

Quality isn't the absence of defects but the presence of value.

Phase 1: The "House of Quality" customer attributes/quality characteristics matrix.

See also: (Git06, ch5.5)

This matrix answers the question "What does a "good product" mean to our customers?"

The definitions of goodness contained in the customer attributes are mapped into the quality characteristics of the product.

So this is where the "voice of the customer" represented by the product attributes is translated into the language of the product quality characteristics.

1 VOC 1 Regulatory Req 1 Customer Importance Rating * Can I use Kano here? 1 Customer rating of Competition 1 Technical Descriptors - Voice of the Engineer * Hvad med VOB? Is that a later phase? 1 Direction of Improvement * Is that like increase/decrease? 1 Relationship Matrix 1 Organizational difficulty 1 Technical analysis of competitor Product 1 Target values for Technical Descriptors 1 Corelation Matrix 1 Absolute Importance

Room 1 in the House of Quality

Room 1 is used to identify, list, and weight primary, secondary, and tertiary "Voice of the Stakeholder" data and benchmark data by stakeholder segment. Examples of stakeholder segments are(Git06, ch5.5):

• "Voice of the Customer" by market segment.
• "Voice of the Employee" by employee segment (top management, middle management, supervisors, employees).
• Voice of the Investor by investor segment.
• Voice of the Supplier by type of supplier.
• Voice of the Sub-Contractor by type of sub-contractor.
• Voice of the Regulator by regulator.
• Voice of the Environment.
• Voice of the Community.

1 list the cognitive images (features) for each stakeholder segment using a systematic (tree) diagram (primary voice, secondary voice, and tertiary cognitive image). $ System: $ Component lvl A: $ Component lvl B: $ Component lvl C: $ Feature or Service: 1 identify the Kano category for each tertiary cognitive image. 1 weight each stakeholder segment on a 0.0 to 1.0 scale, such that the sum of the weights equals 1.00. * Internal experts develop these weights based on revenue or other considerations. 1 establish 0.0 to 1.0 weights for the cognitive images within a stakeholder segment that sum to 1.0.

Room 2 in HoQ - Competition

Room 2 compares your organization with best-in-class organizations with respect to each cognitive image.

Room 2 is not always appropriate in a House of Quality; for example, a new product, service, or process might not have any competition.

1 select a sample of stakeholders from each segment, administer a survey to the selected individuals or organizations. * in each segment using a rating scale for the importance of each cognitive image (1 = very unimportant, 3 = neutral, 5 = very important), * and compute the average importance rating for each cognitive image for each stakeholder segment. 1 rate each competitor's performance on each cognitive image. a. list the "best of the competition" in the columns of Room 2 (list created by internal experts). * "Best of the competition" organizations are market share leaders, innovative providers in respect to quality, cost, service, delivery, safety, environment, and more. a. rate each 'best competitor' on each cognitive image for each stakeholder segment. * The same rating scale is used as the one in the stakeholder survey earlier. 1 compare and contrast all organizations on each cognitive image by stakeholder segment.

Room 3 in the House of Quality

Room 3 is used to translate each cognitive image into one or more product, service, or process CTQs.

CTQs are identified using:

• Product, service, or process knowledge.
• Benchmark information.
• Data from existing QFD tables for similar designs

Team members can ask: "How might we meet the need or want stated by this "Voice?" There are three basic types of relationships between cognitive images and CTQs:

• One cognitive image to one CTQ.
• One cognitive image to many CTQs.
• Many cognitive images to many CTQs.

Room 3 encourages team members to ask the following set of questions about each CTQ, for each stakeholder segment: $ Can we measure this CTQ?: If we can measure the CTQ, how will we measure it and how will we ensure data integrity? If there are different methods and people involved in collecting the measurements, can we perform a Gage R&R (i.e., a repeatability and reproducibility) study on this measure of how well we are achieving the CTQ requirement? * Is this CTQ important to one or more stakeholder groups? * Does it relate to one or more cognitive images? * Will improving this CTQ improve the product, service, or process? * Will the stakeholder pay to collect and analyze data on this CTQ? $ Is the CTQ easy to understand?: * Can employees interpret the measurement associated with the CTQ? * Do employees understand why the CTQ is important to stakeholders? $ Does the CTQ have a direction?: * Does the CTQ have a nominal value and specification limit(s)? * Does the CTQ assist in good, cost-effective, timely decision making?

TABLE 5.4 Examples of Relationships Among Cognitive Images and CTQs |Cognitive Image(s) |CTQ(s)| |One-to-One Relationship| | |Guaranteed on-time arrival at destination by shuttle bus.| Arrival at destination within 15 minutes of arrival to shuttle bus station| |^| (% of riders arriving at destination within 15 minutes of arrival to shuttle bus station).| |One-to-Many Relationship| | |Create a Visitor's Center in the Ponce de Leon parking garage.| CTQ1—Fifty additional parking spaces reserved for visitors (Y/N).| |^| CTQ2—Information Center to answer questions and provide directions(Y/N).| |^| CTQ3—Kiosk for bookstore (U of Miami paraphernalia) (Y/N).| |^| CTQ4—Kiosk for Admissions (U of Miami brochures and bulletins)(Y/N).| |^| CTQ5—Kiosk for food services (vending area) (Y/N).| |^| CTQ4—Shuttle car service for VIP visitors (Y/N).| |Many-to-Many Relationship| | |Cease using the services of a towing company. End the $80 towing fee.| Begin "booting" cars that were previously towed (Y/N).| |^| Charge a $50 booting fee (Y/N).|

Room 4 in the House of Quality

Room 4 presents the relationships between the cognitive images in Room 1 and the CTQs in Room 3, and prioritizes the CTQs by stakeholder segment.

A team of internal experts determines and presents the relationship between each cognitive image and CTQ.

It is important for the internal experts to document the logic for the cell relationship values. If this is not done, the entire analysis may collapse under scrutiny by management.

The scale:

• 9 = strong relationship (positive or negative) between a cognitive image and a CTQ.
• 3 = moderate relationship (positive or negative) between a cognitive image and a CTQ.
• 1 = weak relationship (positive or negative) between a cognitive image and a CTQ.
• 0 = no relationship (blank cell) between a cognitive image and a CTQ.

1 calculate each weighted cell value by multiplying each cell relationship value by its appropriate row importance rating. 1 compute the column totals for each stakeholder segment by adding the weighted cell values down the column for each CTQ. 1 compute the weighted column total for each CTQ overall stakeholder segment by multiplying the segment weight by the segment column total for each CTQ and summing over all segments. 1 calculate the relative percentage for each CTQ by dividing the weighted value of each CTQ overall segment by the total of all of the weighted values for all CTQs overall segment. 1 study the empty rows and/or columns of Room 4. * An empty row indicates a stakeholder voice that is not being serviced by any CTQ. * This represents the opportunity to fill an unmet stakeholder need or want. * An empty column indicates a CTQ that is not related to any stakeholder need or want. * This represents an opportunity to eliminate an unnecessary CTQ.

Room 5 in the House of Quality

• It helps to uncover perceptual problems with your product, service, or process, rather than technical problems.

Room 5 is used to compare your organization with the best-in-class organizations with respect to each CTQ (use internal experts and benchmarking to make the comparisons).

Room 5 assumes that there is a benchmark product, service, or process. However, if no benchmark exists, as in the case of a new invention, then Room 5 is vacant.

Room 5 involves team members assessing the perceived or actual performance of your organization and best-in-class competitors for each CTQ.

• Internal experts use a 1 to 5 scale to score the performance of your product, service, or process using benchmark data.
• Internal experts use another 1 to 5 scale to score the performance of your best-in-class competitor's products, services, or processes using benchmark data.
• Frequently, team members only benchmark 50% of all CTQs.

Room 6 in the House of Quality

Room 6 is used to set target (nominal values) and specification limits for each CTQ .

Establish targets (nominal values) and specification limits for each CTQ, using:

• product
• service
• process knowledge
• technical expertise.

$ Targets (nominal values): identify the ideal level of performance necessary to satisfy stakeholders, overall or by stakeholder segment.

• Unaffected/untainted by:
  • not on company constraints.
  • not set on current or projected process capability. $ Specification limits: are developed by determining the minimum (LSL = Lower Specification Limit) and/or maximum (USL = Upper Specification Limit) level of performance that will satisfy the customer.
  • They identify the performance at which a product, service, or process is deemed nonconforming.
  • Recall, this is called the "goal post" view of quality

Team members should set to surpass the needs and want of relevant stakeholder segments.

• Some Six Sigma professionals define CTQs as specifications (Max 70dB at highway speed)

• or others define CTQs as general needs("quiet" car riding) with specifications identified later.

• A one-sided specification limit is an upper or lower boundary on the acceptable performance of a quality characteristic (CTQ or CTP).

• A two-sided specification limit is an upper and lower boundary on the acceptable performance of a quality characteristic (CTQ or CTP).

| Waiting Time | Very Satisfied (1) | Satisfied (2) | Neutral (3) | Dissatisfied (4) | Very Dissatisfied (5) | |00<15 min. | 100 | 0| 0| 0| 0 | |15<30 min. | 95| 5| 0| 0| 0 | |30<45 min. | 25| 50| 25| 0| 0| |45<60 min. | 0| 0| 0| 75| 25| |60<75 min. | 0| 0| 0| 0| 100| |75 + min. | 0| 0| 0| 0| 100|

• an upper specification limit of 30 minutes is acceptable, if a 5% not "Very Satisfied" rating is acceptable (USL = 30).
• if a 5% not "Very Satisfied" rating is not acceptable, the upper specification limit is 15 minutes (USL = 15).

| Waiting Time | Very Satisfied (1) | Satisfied (2) | Neutral (3) | Dissatisfied (4) | Very Dissatisfied (5) | |4 days early |0 |0 |0 |0 |100| |3 days early |0 |25 |50 |25 |0| |2 days early |60 |40 |0 |0 |0| |1 day early |98 |2 |0 |0 |0| |On time |100 |0 |0 |0| 0| |1 day late |95 |5 |0 |0 |0| |2 days late |50 |50| 0| 0 |0| |3 days late |0 |25 |50| 25| 0| |4 days late |0 |0 |0| 0 |100|

that 1 day early is the LSL and 1 day late is the USL on number of days a delivery can be off target before there is serious erosion in the level of customer dissatisfaction. A stricter interpretation may indicate that only on-time delivery (0 days early or late) is acceptable to customers. The specification depends on what the company is trying to achieve with the product, service, or process.

Room 7 in the House of Quality

Team members use Room 7 to quantify and study the relationships among the CTQs and to create trade offs among the CTQs.

1 establish the directional goals for each CTQ, using the following scale: * (+) = customer satisfaction increases as we increase this CTQ. * (0) = customer satisfaction increases as we get closer to target for this CTQ. * (-) = customer satisfaction increases as we decrease this CTQ. 1 state the strength of the relationship between CTQ pairs in the triangular portion of the table, using the following scale: * (++) = strong positive relationship between a pair of CTQs. * (+) = moderate positive relationship between a pair of CTQs. * (-) = moderate negative relationship between a pair of CTQs. * (- -) = strong negative relationship between a pair of CTQs. 1 define tradeoffs between negatively related CTQs. This requires much time and thought to satisfy the conflicting needs and wants expressed by the CTQs. * Customer's needs and wants, not organizational constraints, should be considered when creating tradeoffs between negatively related CTQs.

$ Deploying Stakeholder Voices Beyond CTQs.: Team members deploy the various "Voices of Stakeholders" beyond the CTQs into product parts or service steps, manufacturing or delivery operations, and production or service requirements. The construction of a cascading set of QFD matrices entails a significant amount of effort (see Table 5.13). It is important that the effort be justified by financial or customer satisfaction benefits.

2. Phase 2: The Parts Deployment quality characteristics/parts characteristics matrix.

This matrix answers the question "What parts of the product deliver the quality characteristics our customers want?"

Critical quality characteristics are mapped into parts and their characteristics. (Note that the design, and therefore the necessary parts, is already determined. There is no design in the software development sense in this model, as a parts supplier in a build-to-print environment cannot do systems design; it can only upgrade the existing product. It is constrained to only make changes within parts or within its production process.)

3. Phase 3: The Process Planning part characteristics/process parameters matrix.

This matrix answers the question "Where in our manufacturing process can we affect the critical parts characteristics?"

Critical parts characteristics are mapped into process steps and parameters. So this is where the "voice of the customer," translated into critical process steps and parameters, reaches the factory floor.

4. Phase 4: The Production Planning process parameters/production requirements matrix.

This matrix answers the question "What should the production plans, procedures, and inputs be for the key process operations to produce the key parts (with their critical characteristics) to satisfy the customer?"

So now the "voice of the customer" has reached the machine operators, and it determines the settings on the production machinery.

In software development, when we are making design decisions during the design phase and are choosing which implementing technology to use, it is useful and appropriate to examine logical or design conflicts—and the roof can be helpful. But that is in the design phase, not in the analysis phase, and the "House of Quality" is an analysis phase matrix.